a motorboat maintains a constant speed of 38 miles per hour. it takes 30 minutes to travel upstream and 27 minutes back. what is the speed of current?​

Answer:r = 2 [stream's speed is 2 mph downstreamStep-by-step explanation:RemarkThe distances traveled [upstream and downstream] are the same.If it takes longer to go upstream, it means the speed of the current is going against him. So the rate is 38 - r where r is the speed of the current.The rate of the downstream is 38 + r because it takes him less time to go downstream and the current is helping him go.The times are givenGivensTime Upstream = 30 minutesTime Downstream = 27 minutesDistance upstream = d1Distance downstream = d2rate upstream:        38 - rrate downstream: 38 + rd1 = d2Formulad1 = d2d1 = (38 - r) * 30d2 = (38 + r) *27(38 - r) * 30 = (38+r)*27SolutionRemove the brackets on both sides.38*30 - 30*r = 38*27 + 27r                    Add 30r to both sides38*30 - 30r + 30r =38*27 + 27r + 30r  Combine the numbers1140 = 1026 + 57r                                   Subtract 1026 from both sides.114 = 57r                                                  Divide by 57114/57 = 57r/57r = 2